n this study a new approach was used to assess the ecosystem functioning in a marine coastal area subjected to multiple and diffuse contamination. An integrated planktonic/benthic view was obtained by merging information from the analysis of both the active (i.e. the microphytobenthos sensu stricto) and the resting (i.e. the resting stages produced by plankton) component of the microbenthic community. Seven stations were sampled within the port of Trieste. No major differences in total abundances of active microbenthos were observed, but a selection of stress-resistant species like Nitzschia cf. commutata and the reduction of more sensitive ones were highlighted nearby the main productive activities. Conversely, the resting microbenthos densities were higher in this area, and represented by key species like some potentially toxic Alexandrium, the heterotrophs and some calcareous-walled species, i.e. Calciodinellum albatrosianum, that were clearly linked to contamination. The photosynthetic capability of active microbenthos did not seem to be affected by contamination. In contrast, the reduced thickness of the oxic layer and the maximum oxygen consumption rates observed in sediments nearby the productive activities were likely ascribable to high TOC contents and the presence of metals in reduced chemical form.
Benthic-pelagic coupling and ecosystem functioning: the role of active and resting microbenthos
Rubino F;Belmonte M;
2016
Abstract
n this study a new approach was used to assess the ecosystem functioning in a marine coastal area subjected to multiple and diffuse contamination. An integrated planktonic/benthic view was obtained by merging information from the analysis of both the active (i.e. the microphytobenthos sensu stricto) and the resting (i.e. the resting stages produced by plankton) component of the microbenthic community. Seven stations were sampled within the port of Trieste. No major differences in total abundances of active microbenthos were observed, but a selection of stress-resistant species like Nitzschia cf. commutata and the reduction of more sensitive ones were highlighted nearby the main productive activities. Conversely, the resting microbenthos densities were higher in this area, and represented by key species like some potentially toxic Alexandrium, the heterotrophs and some calcareous-walled species, i.e. Calciodinellum albatrosianum, that were clearly linked to contamination. The photosynthetic capability of active microbenthos did not seem to be affected by contamination. In contrast, the reduced thickness of the oxic layer and the maximum oxygen consumption rates observed in sediments nearby the productive activities were likely ascribable to high TOC contents and the presence of metals in reduced chemical form.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
